A former U.S. Marine and two companions have been arrested after police say he beat his pregnant wife in their California apartment.

Brian Corder, 26, allegedly beat his wife, who is four months pregnant, June 16, with help from his girlfriend, Fredericka Carmouche, 19, and their friend, Stephon Crutchfield, 21, according to ABC News Station KABC-TV.

The unborn child and victim are expected to make a full recovery and remain at an undisclosed hospital in stable condition. Police did not release the name of the victim.

"Thank God she survived; she is a very, very tough lady," Los Angeles Police Det. Chris Casey said.

Police say the attack took place around 12:40 a.m. at Corder's apartment, which he shared with the victim, in Northridge, Calif. Detectives initially thought the victim had been sexually assaulted. They did not say what kinds of weapons were used in the alleged attack.

"These investigators are very talented, and things weren't adding up right, and they pursued the leads and evidence which compiled together to get the right three people," Casey said of the allegations.

Corder, Carmouche and Crutchfield have been charged with conspiracy and attempted murder. They are behind bars with bail set at $1 million each.